Solution: In the 1850s, Michael Faraday prepared ruby-red colloids
of gold nanoparticles in water that are still stable today.
These brightly colored colloids look like solutions. What
experiment(s) could you do to determine whether a given colored
preparation is a solution or colloid?

Problem

In the 1850s, Michael Faraday prepared ruby-red colloids
of gold nanoparticles in water that are still stable today.
These brightly colored colloids look like solutions. What
experiment(s) could you do to determine whether a given colored
preparation is a solution or colloid?